Storage water heater



Aug. 21, 192s.

E. S. STACK STORAGE WATER HEATER Filed Oct. 20. 1921 Patented Aug. 21,1928.

UNITED STATES ELMER S. STAUK, 0I' BomVIInLE, MASSACHUSETTS.

STORAGE WATER HEATER.

Application ma october 2o, 1921. seriai no. 509,087.

The resent invention relates to water heaters of t 1e type by whichwater may be heated and stored, ready for use when needed. Such heatersare commonl known in the art' as storage systems and t ey usuallyconsist of a tank or boiler and a gas burner arranged to direct theproducts of combustion of gas against a part of such boiler, togetherwith accessory connections and automatic heat controlling meansregulated by the temperature of the stored water.

Storagek heaters or systems as heretofore made have caused trouble andhave suffered loss of efliciency through collection of sediment in thebottom of the storage reservoir and condensation of water from theproducts of combustion of the heating flame upon the outside of theboiler or water heater. Sediment accumulated in the parts of the systemagainst which the heating flame is directed has a blanketing effect,hindering the flow of heat into the water and causing the metal of theboiler or heating unit to become overheated. When overheating occurs themet-a1 may be burned or melted through, or the heat insulating effect ofthe sediment blanket may keep it at a high temperature after the flamehas been shut off and until cold water has come into contact with theheated parts, with resulting liability of warping and cracking themetal. Further, sediment in the arts of a boiler exposed to heat causes`disco oration of the water, because in those parts the water is inmotion such that it stirs up the sediment and carries some of it to thedischarge point. And the presence of sediment there induces depositionof more sediment because the heating of the metal to high temperaturecauses rust to form rapidly, and the retardation of. water circulationcauses the water to become excessively hot and minerals or other foreimatter carried in solution and suspension 1n the water to beprecipitated Condensation of water from the products of combustionoccurs when the part of the heating system on which the flame impingescontains water cold enough to reduce the temperature of such productsbelow the dew point of the water vapor which is always a part of suchproducts of combustion. The water of condensation from this source has astrongly corrosive action and rapidly deteriorates the parts of thesystem with which it comes in contact.

My object has been to overcome the ditriculties and sources of troubleherein outlined the invention consists being explained in connectionwith the following detailed description o f the pgart-icular apparatusshown in said drawing. igure 2 is a cross section on line 2 2 of Figure1.

Herein 1 represents a storage tank having an upper head 2, a bottom head3 and two inner heads or partitions 4 and 5. The partition 5, which isthe innermost one of these inner heads or partitions is convex upwardlyand forms an acute angle 6 with the sides of the tank. An opening 7 isformed through the part1t1on 5, preferably at the highest point thereof,which is also its center; but at any rate well above the junction ofthesides of the partition with the side walls of the tank. Both the bottomhead 3 and the intermediate head 4 are preferably convex downwardly; andthe intermedia-te head joins an inner shell 8 of smaller diameter thanthe outer or main shell of the tank and to which it is connected by aring 9. The head 4 and inner shell 8 together form a partitionintermediate the bottom head and the innermost partition. Thus there isprovided between the heads 3 and 4 a water chamber 10, and between theinner and outer shells a water leg 11 of considerable height joining thewater chamber 10.

A heating chamber 12 hangs down from the bottom head 3 and is connectedtherewith and has communication with the chamber 10; and a conduit 13runs from the intermediate head 4 into the heating chamber and providescommunication from the latter to the space or chamber 14 between theintermediate and inner heads. Outside of the conduit 13 and within theconnection between the chambers 10 and 12 is a space 15 suilicientlywide to permit free flow of water.

A gas burner 16 is arranged beneath the heating chamber and is adaptedto direct a flame of gas against the outside of said chamber. The burneris supplied with gas by a pipe 17 in which is arranged a valve 18controlled by a thermostat 19 in any well known or other suitable way soas to diminish or out off entirely the supply of s to the burner whenthe water in the tank 1s heated to a prescribed temperature, and toincrease the supply of gas to the burner when the water temperaturedrops below aprescribed degree. 20 represents a tube supplying a pilotburner from a oint at the supply side o statical y controlled valve 18.

The pipe supplying water to be heated is shown at 21 as passing throughthe upper head of the tank, and as having also a branch 22 extendingdownward and opening through the Side of the tank at a low point. Ifdesired the inlet opening at the top of the tank may be omitted orclosed and the entire cold water supply be delivered to the lower partof the tank through the pipe 22.

The heated water is delivered through a pipe 23 which has a connectionwith the interior of the tank through the upper head 2 and is connectedwith a pipe 24 which ma be called, for the purpose of convenient denition, an eduction pipe, running downward to a connection 25 with thewater leg 11.

26 represents a tap for drawing off water and sediment from the space 6in the tank below the openin 7 and above the inner head 5. 27 is astacli for conducting away products of combustion from the flame and 28is a pipe terminating in a tap 29 for drawing off all of the water inthe lower chambers when there is occasion for entirely emptying thetank, so as to prevent freezing when the premises 1n which the system isinstalled are unoccupied during the cold weather.

The entire tank and its adjuncts are supported by a shell 30 whichsurrounds and encloses the burner and the heating chamber, beingsupported in turn by legs 3l and being open at the bottom to give accessfor air to support combustion of the gas. A bar or beam 32 crossing thelower part of the shell 30 supports the burner.

When in operation, the boiler is full of water in all of its chambers,and cold water is admitted through the constantly open inlet connectionsto replace any hot water which may be drawn off. When the water in theregion of the thermostat is cold, gas is admitte to the burner and theflame applies heat to the Water in the heating chamber 12. As this waterrises in temperature, it iiows upward through the passage 15 into thechamber 10 and` the water aleg 11, and thence through the eduction pipe24, cooler water from the bottom of the main chamber then constantlyowing through the passage 7, chamber 14 and conduit 13 to take the placeof the hot water. When no hot water is being drawn o from the outletpipe 23 a constant circulation takes place, for the hot water enters theupper part of the boiler through the 'connection o the draw-01T ipetherewith. When the water in the main c amber down to the level of thethermostat has been heated to the thermothe required degree, the su plyof gas to the burner is shut oi, but w en hot water is withdrawn, theincoming cold water cools the thermostat and causes the as controllingvalve to be a ain opened. Preferably the outlet of the co d water supplypipe 22 is at or near the level of the thermostat, as shown, in orderthat the thermostat may be quickly affected by the entering cold water.

ATroubles due to collection of sediment are avoided because the locationof opening 7 above any other part of the inner partition 5 preventssediment in any ap reciable quantity passing to the lower cham ers, andthe upward convexity of the inner partition 5 causes all of the sedimentwhich settles out of the water to collect in the angle 6, from which itmay be drawn oi from time to time throu h the tap 26. There is noopportunity for t e heating flame and products of combustion thereof toimpinge on the surfaces against which sediment may collect, for thewalls bounding the angle 6 are insulated from the products of combustionby the water in the chambers 10 and 14. There is also preferably, anexternal jacket 33 of insulatin material which surrounds the upper parto the tank and rests on a rim or flange 34: located between the lowerextremity of the angle 6 and the stack 27. Condensation is avoidedbecause the cold water is not admitted directly into the heatingchamber` but is first passed through the chamber 14 which is so muchlarger than the conduit 13 that the water remains in it for aconsiderable time. Being largely surrounded by the hot water in thechamber 10, the water in chamber 14 becomes heated by conduction of heatfrom the surrounding Water to the degree that when it finally enters theheating chamber 12 its temperature is too high to condense the watervapor in the products of combustion from a heating flame.

It is not to be inferred from the description of the use of this heaterfor heating water, or from the reference to burning gas as the heatinagent, that the protection which I claim is imited to that particularuse or to the employment of that particular heating agent. The inventionresides in a heatin apparatus having characteristics substantia ly asherein described and hereinafter claimed for all uses to which it may beapplied, and combined with any heating agent or means which may bepractically used with it. So far as the new steps of the presentinvention are concerned, it is not important whether or not the heatingmeans is regulated by an automatic thermostatic device, since the valueof such a device is merely to prevent damage to the apparatus fromoverheating and to prevent waste of the heating agent; effects which,while practically necessary, are collateral to the particular objectsserved by my invention.

In this specification the term boiler is lul) llU

used in the sense in which it is commonly applied to hot water storagetanks for domestic use and contains no implication that the water mustbe heated to the boiling temperature.

lVhat I claim and desire to secure by Letters Patent is:

Al. A water heater comprising a tank having a bottom head, a heatingchamber depending from said bottom head incommunication with the spaceenclosed by such head, and an inner partition crossing the interior otthe tank above such head, said partition being constructed and arrangedwith a portion of its structure at a relatively high level, and anotherportion at a relatively low level forming a pocket tor collection ofsediment, and having an opening in said portion at the relatively highlevel for passage of water into the space between itself and the bottomhead, and a. tap leading from said pocket.

2. A water heater comprising a tank having a bottom, a heating chamberbelow said bottom, means for applying heat to said heating chamber, aninner partition above said bottom delimiting from the interior of thetank a lower chamber which is in flow-receiving communication with theheating chamber below said inner partition, whereby hot water from theheating chamber is enabled to deliver heat to the water above said par,-tition, and a conduit arranged to conduct water from above the innerpartition into the heating chamber'.

3. A water heater comprising a tank having a bottom head, a heatingchamber depending from said bottom head and having a water connectionwith the space enclosed by the head, heating means arranged to applyheat to said heating chamber, an inner partition arranged to delimitfrom the balance o'l the tank a space adjacent to the said bottom head,an eduction pipe for conducting hot water from said space, means foradmitting cold water into the tank above said inner partition, and aconduit arranged to lead water from the space abovethe inner partitioninto the heating chamber.

4. A stoage water heater comprising a tank having abottom head and twoinner partitions, one above the other, the upper one of said innerpartitions being connected at its edges to the sides of the tank on acontinuous substantially closed line, being bulged upwardly from saidline and having an opening above the plane ot such line, a heatingchamber beneath the bottom head and having a water conducting connectionwith the space above such head, and a conduit leading through the lowerone of said inner partitions into said heating chamber.

5. A storage water heater comprising a. tank having a bottom head andinner partitions above said head dividing the interior of the tank intoa lower chamber, an intermediate chamber and an upper chamber, andcomprising also a heating chamber in communication with both the lowerchamber and the intermediate chamber, means for applying heat to saidheating chamber, a hot water eduction pipe leadingfrom the lowerchamber, a supply conduit leading to the upper chamber, the intermediateand lower chambers being in thermal contact whereby water in the formeris given a preliminary degree of heat before passing to the heatingchamber; the partition between the intermediate and upper chambershaving an opening for How of water and being otherwise constructed toentrap sediment settling from the water and prevent the passage of suchsediment to the heating chamber.

6. A water heater comprising a tank having an interior partitionarranged to form two distinct inner chambers, means for conducting coldwater to one of said chambers, means tor conducting heated water fromthe other chamber, an exterior heating chamber, a flowdeliveringconnection from said exterior chamber with said heated water chamber, aflow connection from the cold water chamber through said partition andthrough the heated water chamber to said exterior chamber, and heatingmeans arranged to apply a heating agent to said exterior heatingchamber.

7. A water heater comprising a tank having a heating chamber the wallsot which are exposed to the products of combustion of a flame, andpartitioning means within the tank arranged to delimit two separatedspaces in separate communication with the heating chamber, means forconducting water into one ot said spaces, and means for conducing wateraway from the other space; the last named space being arranged betweenthe heating chamber and the iirst named space.

8. A water heater comprising a tank and a gas burner beneath the tankadapted to direct a flame against the bottom portion thereof said tankincluding partitions delimiting a lower heating chamber with which theflame from said burner comes directly in contact, a chamber above saidheating chamber having communication with the latter for receptionv ofheated water therefrom, an eduction pipe leading Jfrom the second-namedchamber into the upper part of the tank, a partition delimiting saidsecond-named chamber from the upper part ot the tank and being entirelyshieldedtroln the flame, and a conduit leading from the space above saidlast mentioned partition into said heating chamber and arranged toconduct water thereto exclusively from the second-named chamber.

In testimony whereof I have aiiixed my signature.

ELMER S. STACK.

